Too many variables to estimate what someone may or may not be able to gain unless you had a pretty solid logged track record which doesn't appear to be the case.
Why not just resign yourself to a period of bulking and leave the pounds of muscle out of it. Have a plan (hugely important to any goal and this is no different), work hard at it (plan makes you work smart, you are responsible for working hard), periodically reevaluate where you are and if any changes need to be made. If everything is in line, you will gain as much as you can gain. Whether that's 5lbs or 30lbs it will be your best effort and ultimately the willingness, determination, and ability to put forth one's best effort and execute a plan over a prolonged period is far more indicative of a person's calibur than the amount of muscle they carry.